CORNISH: And if a new plan for one-way space travel carried out, the last frontier for a very few brave astronauts, because although returning astronauts safely to Earth used to be the most important part of any space mission, some scientists now say the only way to cut the high cost of space exploration past our small moon is to eliminate the return trip.

Paul Davies is a physics professor at Arizona State University, and he co-wrote an article in the latest Journal of Cosmology, titled "To Boldly Go: A One-Way Human Mission to Mars."

Dr. DAVIES: Well, I think we've all had this dream of going to Mars. It's been something that, for decades, has been proposed. But it's one of these on-again, off-again projects because it is so phenomenally expensive. But by making the trip one-way, you cut the cost dramatically, not just 50 percent, probably about as much as 80 percent.

Really, the point about this is that getting to Mars is a major drama anyway. It would take probably at least six months. So if you're going to do a roundtrip and going to spend a considerable amount of time on the Red Planet, the whole thing is going to be a, you know, two, maybe even three-year project. You might as well stay. If Mars is worth going to, it's worth staying on. What we're advocating is the beginning of a permanent human presence on the Red Planet.

CORNISH: I noticed in your paper, you went out of your way to say this is not a suicide mission.

Dr. DAVIES: Yeah.

CORNISH: Do you think that's how it comes off?

Dr. DAVIES: It's really important to realize this is not a suicide mission, that we're not saying to the astronauts, well, off you go, and when you get there, you've got enough food and oxygen for a few days, and then you're dead.

CORNISH: But then who do you see doing this?

Dr. DAVIES: The least problematic aspect of this is the volunteers.

CORNISH: Oh, okay.

(Soundbite of laughter)

Dr. DAVIES: My mailbox is absolutely overflowing with people volunteering to go. Ideally, you would want people whose life expectancy is not already very great. So if, for example, you send somebody in their 60s who might expect to have a 10 or 20-year life span ahead, well, that may get reduced as a result of the privations of the trip to, say, 10 years. But I think that that is an acceptable trade-off, particularly for a scientist, because don't forget, if you send a scientist to Mars, it's like a kid in a candy store, that they would be able to do sensational work for the rest of their lives, not only be a trailblazer for human presence on the Red Planet but to carry out groundbreaking scientific work of a sort that you could just never, ever do here from Earth.

CORNISH: And you titled your article "To Boldly Go." Do you think that we are no longer boldly going? I mean, are we sort of afraid now of space travel?

Dr. DAVIES: I followed the space program ever since the days of Apollo. I think many of my generation were inspired by this vision that going to the moon was the first step on a ladder that led to the stars.

But we do seem to be stuck in near-Earth orbit, and it's really rather depressing. I do think we have lost that zeal, that vision.

CORNISH: Is it just more evidence that space travel needs to be something that's done through private means, private money and private industry?

Dr. DAVIES: To be realistic, I think the only way that this is going to happen would be if a consortium of space agencies, not just NASA but European Space Agency, Russia, China, India, combine together, and there's a big private input, as well.

CORNISH: What kind of preparation would have to be done on the planet before we could get any astronauts out there?

Dr. DAVIES: They're going to need a power source. That has to be sent on ahead. The ideal thing would be some sort of nuclear reactor. They will also need supplies of basic materials and medical materials and above all, food.

There's not going to be too many culinary delights. Really, this isn't a joy ride. You have to understand that the motivation for doing this is fantastic, groundbreaking science.

CORNISH: Would you be on this list of volunteers?

Dr. DAVIES: Nope. I have to say I'm not (unintelligible)...

(Soundbite of laughter)

Dr. DAVIES: I'm perfectly happy with my life down here on Earth. I'm a dreamer, I'm a visionary, but I'm firmly stuck down here on Earth.

CORNISH: That's Paul Davies. He's a physics professor at Arizona State University. He co-wrote the article "To Boldly Go: A One-Way Human Mission to Mars," published in the current issue of the Journal of Cosmology.

Paul Davies, thanks for taking the time to talk with me.

Dr. DAVIES: Well, it's been my pleasure. Thank you.

CORNISH: Now, Buzz Aldrin is no stranger to space missions. He was the second man to set foot on the moon in 1969. While he supports the philosophy behind Paul Davies' idea, he says labeling the Mars trips as one-way missions isn't very good PR.

Mr. BUZZ ALDRIN (Former Astronaut): The label of settlement and colony development is more appropriate. And I think that...

CORNISH: And Buzz Aldrin says if the U.S. doesn't settle and colonize the Red Planet, someone else will.

Mr. ALDRIN: China and India and others want to explore with humans outward in the solar system. It is inevitable that humans will go there. It's not inevitable that the U.S. will lead.

CORNISH: Former astronaut Buzz Aldrin on prospects for travel to Mars.

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